PARTICLE SIZE EFFECT ON MAGNETIC AND TRANSPORT PROPERTIES OF La0.7Ca0.3MnO3 NANOPARTICLES

S. Qaseem, A. Mumtaz, S. K. Hasanain, K. Maaz

Abstract


La0.7Ca0.3MnO3 nanoparticles have been synthesized by modified citrate route with particle sizes of 20, 26 and 32 +3 nm respectively. The structural characterization has been performed by XRD and TEM analyses while magnetic characterization has been performed by vibrating sample magnetometer (VSM). This work presents the study of size effects on magnetic and electrical properties of Ca-doped CMR nanoparticles (La0.7Ca0.3MnO3). Different particle sizes have been prepared by a wet chemical route. Magnetic characterization reveals that magnetization increases with the increase in the particle size and the magnetic transition temperature for larger particles is the same as in the bulk (258K). The ferromagnetic and resistive transitions are however broad compared to the case of bulk presumably due to the role of the surface. The metal-insulator transition temperature is found to be at 158K while the resistivity shows anomalous low temperature behavior with an upturn at low temperatures presu due to coulomb blockade effects. Furthermore, the field dependence of the resistivity displays nonmonotonic behavior and is explained in terms of the field assisted tunneling between grains. PACS: 73.23 Hk; 73.63 –b; 75.47 –m; 75.47 Gk. 75.75 +a

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References


V. Helmot, J. Wecker, B. Holzapfel, L. Shultz

and K. Samwe, Phys. Rev. Lett. 71, No. 14

(1993) 2331.

W.E. Pickett and D.J. Singh, Phys. Rev. B

, No. 3 (1996) 1146 also C.N.R. Rao, R.

Mahesh, A.K. Raychaudhuri and R.

Mahendiran, J. Phys. Chem. Solids 59, No. 4

(1998) 487.

F. Rivadualla, L.E. Hueso, J. Rivas, M.C.

Blanco, M.A. Lopez-Quintela and R.D.

Sanchez, J. Magn. and Magn. Materials 203

(1999) 253.

J. Rivas, L.E. Hueso, A. Fondado, F.

Rivadualla and M.A. Lopez-Quintela, J.

Magn. and Magn. Materials 221 (2000) 57.

M.A. Lopez-Quintela, L.E. Hueso, J. Rivas

and F. Rivadulla, Nanotechnology 14 (2003)

K. S. Shankar, S. Kar, G.N. Subbhanna and

A.K. Raychaudhuri, Solid State Communications 129 (2004) 479.

M. Ziese, Rep. Prog. Phys. 65 (2002) 143.

P. Sheng, B. Abeles and Y. Arie, Phys Rev.

Lett. 31 (1973) 44.

A. Gupta et al., Phys. Rev. B 54 (1996)

J. S. Helman and B. Abeles, Phys. Rev. Lett.

(1976) 1429.

Li. Balcells, J. Fontcuberta, B. Martinez and

X. Obradors, Phys. Rev. B 58 (1998) 14697.

P. Raychaudhuri, K. Sheshadri, P. Taneja, S.

Bandyopadhyay, P. Ayub, A.K. Nigam, R.

Pinto, S. Chaudhary and S.B. Roy, Phys.

Rev. B 59 (1999) 13919.

S. Mitani, S. Takahashi, K. Takanashi, K.

Yakushiji, S. Maekawa and H. Fujimori, Phys.

Rev. Lett. 81 (1998) 2799.

J. Inoue and S. Maekawa, Phys. Rev.B. 53

(1996) R11 927.

T. Zhu and J. Wang, Phys. Rev. B 60, No. 11

(1999) 918.

J.H. Choy, D.H. Kim, C.W. Kwon, S.J. Hwang

and Y.I. Kim, J. of Power Sources 77 (1999)

T. Yi, S. Gao, Xing Qi, Y. Zhu, F. Cheng,

B. Ma, Y. Huang, C. Liao and C. Yan, Journal

of Physics and Chemistry of Solids (2000)

X.X. Zhang, J. Tejada, Y. Xin, G.F. Sun,

K.W. Wong and X. Bohigas, Appl. Phys. Lett.

(1996) 3596.

P. Schiffer, A.P. Ramirez, W. Bao and S.W.

Cheong, Phys. Rev. Lett. 75 (1995) 3336.

N. Zhang, W. Ding, W. Zhong, D. Xing and Y.

Du, Phys. Rev. B, 56 (1997) 8138.

J. Dai and J. Tang, Phys. Rev. B 63 (2001)

Wang et al. Appl. Phys. Lett. 74 (1999) 2212.


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